A valve is arranged in a flow passage in order to control the flow rate of fluid. One of prior art references pertaining to this kind of valve is a technique disclosed in Japanese Patent Application Laid-open Publication (Kokai) No. Hei 10-252913 A.
A valve such as the one disclosed in Japanese Patent Application Laid-open Publication (Kokai) No. Hei 10-252913 A includes a spool having a cylindrical shape, a valve seat press being fitted into the spool and then caulked, and a valve body provided to be capable of abutting the valve seat.
The valve seat has a groove formed in an outer circumference thereof toward an axis line. After the valve seat is press fitted into the spool, the spool is pressed toward the groove. It makes it possible that a part of the spool is pressed into an inside of the groove. In other words, the valve seat is caulked by the spool. By caulking after press fitting, it makes it possible to secure those components to each other more rigidly.